It is well known to provide various types of utility trailers to be attached to other vehicles for moving materials and items from location to location easily. During the use of such trailers, a persistent problem has been and is to provide for the simple, safe and efficient loading and unloading of the item to be carried on the trailer. Various solutions and/or features which may be integral or used in conjunction with utility trailers have been proposed.
One of the most well represented of such solutions is exemplified by U.S. Pat. No. 3,972,428 (to Love, Jr., et al.) which discloses a trailer which includes a loading ramp construction pivotally mounted on the trailer and movable between a loading position in which the ramp extends rearwardly from the trailer and a tailgate forming position into which the ramp may be locked. While the disclosed loading ramp construction represents an advance over prior art trailers which are not equipped with such pivotally attached ramp devices, it remains necessary for the vehicle operator or an assistant to physically move the ramp into its tailgate position and ensure that it is locked into that position.
Another type of solution proposed to enable the efficient, safe and convenient loading of utility trailers is shown in U.S. Pat. No. 4,372,727 (to Fredrickson, et al.) wherein a multiple fold powered ramp for a trailer is described. The ramp comprises multiple stages which are pivotally connected and may be folded upon themselves for storage and unfolded so that they form an extension of the main ramp portion for loading and unloading. However, the disclosed ramp requires a complicated arrangement of hydraulic conduits and pumps for manipulating the various stages
Also well represented in the art, another type of solution proposed to facilitate the loading and unloading of utility tractors is shown in U.S. Pat. No. 4,222,698 (to Boelter) which discloses a trailer assembly that includes a movable frame and a mechanism for adjusting the frame and support portions between a first position and a second position. In effect, the support portions, or bed of the trailer, may be inclined downwardly or tilted by means of the adjusting mechanism to facilitate the loading and unloading of the trailer.
Similarly, U.S. Pat. No. 2,271,071 (to Haber) discloses a trailer type carrier for farm equipment wherein the bed of the trailer may be tilted at an angle to facilitate loading and unloading. This trailer also includes a tailgate which may be pivoted down to the ground to load or unload equipment, and then pivoted to an upright position to maintain the equipment on the trailer.
While these trailers and the associated devices for providing ramps for loading and unloading the trailers represent advances which permit the convenient, safe and efficient loading and unloading of such trailers, there is an efficiency which remains unaddressed. That is, it is necessary for an operator to undertake time consuming, strenuous, and often hazardous steps to manipulate the various ramp devices and trailers into condition for transport movement following the loading of the trailer. Also, should an operator neglect to raise one of these ramp devices before towing of the trailer is initiated, the equipment on the trailer may be discharged and damaged. Also, damage to the trailing ramp is likely to occur.